Page 39 - Academic Press Encyclopedia of Physical Science and Technology 3rd Analytical Chemistry

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578 Analytical Chemistry

TABLE XIV Areas of Future Instrumental Development IV. FUTURE PERSPECTIVES
Area Anticipated development
Naturally, it is difficult to predict the evolution of a dis-
Electroanalytical methods Molecularly designed electrodes, cipline as diverse as analytical chemistry. Table XIV
speciation
indicates a summary of short-term future directions as
Microelectrodes, biological probes
garnered from the present interests and activities of re-
Electrochemical detectors, combination
searchers in the field. One dramatic, rapid change is the
techniques
movement away from sampling technology. Direct in situ
Chromatographic and Specialization methods for difficult
measurement technology is being emphasized in many
separation methods separations (maximization of
column efficiency and methodology areas of analytical chemistry and eventually may largely
presently attained developments in supercede the need to define statistically valid samples
supercritical fluid chromatography, from a bulk sample material.
separation of isomers and Probably the analytical instrumentation of the future
chiral species)
will become more and more automated, but until artificial
Spectrochemical methods Higher yield ion sources for mass
spectrometry intelligence makes its debut in instrumentation, the chem-
ical knowledge of the analyst will always be of paramount
Hyphenated techniques, gas or liquid
chromatography with inductively importance. The intelligent application of any analytical
coupled plasma emission spectroscopy technique will continue to require a good understanding
Minimization of sample preparation of basic physical and chemical theory and a knowledge of
Chemometrics Computer-assisted data manipulation practical experimental limitations.
Expert systems and “intelligent”
instruments
Resolution improvement programs for SEE ALSO THE FOLLOWING ARTICLES
chromatography to speed analyses
Pattern recognition systems
ATOMIC SPECTROMETRY • CHROMATOGRAPHY • DISTIL-
Surface science Angle-resolved electron spectroscopy
LATION • ELECTROCHEMISTRY • ELEMENTAL ANALY-
Molecular information, conformations
SIS,ORGANIC COMPOUNDS • GAS CHROMATOGRAPHY •
Discrete molecular and atomic resolution,
INFRARED SPECTROSCOPY • LIQUID CHROMATOGRAPHY
e.g., for direct sequencing of DNA
• MASS SPECTROMETRY • NUCLEAR MAGNETIC RESO-
NANCE • ORGANIC CHEMISTRY,COMPOUND DETECTION
• RAMAN SPECTROSCOPY
matrix.” If the corresponding “analytical matrix” of x jk is
considered, the following observations apply:
BIBLIOGRAPHY
1. For a determinant of det(γ ik ) = 0, no mapping from
the calibration to the analytical matrix exists.
Bard, A. J., and Faulkner, L. R. (2001). “Electrochemical Methods,”
2. Selectivity can be given a value θ, where Wiley, New York.
Christian, G. D. (1994). “Analytical Chemistry,” 5th ed., Wiley, New
γ ii
− 1, York.
k
θ = min
i=1→n
n=1 γ ik − γ ii Dean, J. A. (1995). “Analytical Chemistry Handbook,” McGraw-Hill,
New York.
A system is fully selective when lim θ →∞, but no Elving, P. J., and Kolthoff, I. M. (eds.) (1978). “Treatise on Analytical
selectivity exists for θ values that are small compared Chemistry,” 2nd ed., Wiley-Interscience, New York.
with zero. Kellneer, R., Mermet, J.-M., Otto, M., and Widmer, H. M. (1998). “An-
alytical Chemistry,” Wiley-VCH, Weinheim.
3. Specificity is a special case of selectivity and
Lindon, J. C., Tranter, G. E., and Holmes, J. L., eds., (2000). “Ency-
generates a single nonzero element (in the calibration clopedia of Spectroscopy and Spectrometry,” Academic Press, San
matrix), which lies on the diagonal. Diego.
4. A partial specificity can be defined when only the Meyers, R. A., ed. (1998). “Encyclopedia of Environmental Analysis
diagonal element in one row can practically be and Remediation,” Wiley, New York.
Meyers, R. A., ed. (2000). “Encyclopedia of Analytical Chemistry
considered to have a nonzero value. A grade of
Applications, Theory and Instrumentation,” Wiley, Chichester.
specificity is numericaily determined by
Skoog, D. A., West, D. M., and Holler, J. F. (1997). “Fundamentals of
Analytical Chemistry,” 7th ed., Saunders, Philadelphia.
γ aa
− 1. Skoog, D. A., Holler, J. F., and Nieman, T. A. (1998). “Principles of
θ a =
n
k=1 γ kk − γ aa Instrumental Analysis,” 5th ed., Harcourt, Philadelphia.